We propose establishment of a research center on adolescent drug abuse treatment research, spanning from treatment development to mechanisms, evaluation and dissemination. The mission of the Center is to: (1) develop improved ADA family-based treatments, (2) test the efficacy and effectiveness of family-oriented as well as existing treatments, (3) develop a greater understanding of the treatment and patient/family characteristics that influence treatment outcome, (4) disseminate through matters related to ADA treatment. Study 1 addresses the clinical and cost effectiveness of residential treatment compared to an intensive, family- based, outpatient modality. Study 2 seeks to uncover universal mechanisms in family therapists' behaviors and family processes that contribute to early outcomes. The proposed Center is organized into three cores: Administrative, Methodology, and Treatment Development, Clinical and Training. Three programs of family based intervention research have collaborated to produce this application. These investigators, Liddle, Szapocznik, and Alexander; have been actively collaborating for over five years. This collaboration has yielded an integrative perspective on core challenges to the field which we have formed into this proposal.